Pure hydrogen low-temperature plasma exposure of HOPG and graphene: Graphane formation?

• Baran Eren,
• Dorothée Hug,
• Laurent Marot,
• Rémy Pawlak,
• Marcin Kisiel,
• Roland Steiner,
• Dominik M. Zumbühl and
• Ernst Meyer

Beilstein J. Nanotechnol. 2012, 3, 852–859, doi:10.3762/bjnano.3.96

• of graphite consists of D and G peaks, around 1350 cm−1 and 1585 cm−1 respectively, which arise from vibrations of sp2-hybridized carbon atoms [23][24][25][26]. The D peak is caused by breathing-like modes corresponding to transverse optical phonons near the K point of the Brillouin zone. It is an

• 2671 cm−1 for single-layer graphene) [25]. The G peak represents the optical E2g phonons at the center of the Brillouin zone. The cross-section for the C–C sp3 vibrations, when available, is negligible for visible excitation. Upon hydrogen plasma exposure of single-layer graphene (Figure 1c, 2nd panel

Nano-FTIR chemical mapping of minerals in biological materials

• Sergiu Amarie,
• Paul Zaslansky,
• Yusuke Kajihara,
• Erika Griesshaber,
• Wolfgang W. Schmahl and
• Fritz Keilmann

Beilstein J. Nanotechnol. 2012, 3, 312–323, doi:10.3762/bjnano.3.35

• phase effect is on the order of 30° for strong polymer vibrations [8][9] but on the order of 400° for strong crystal phonons [3][6]. For molluscs the employment of phosphate in shell architecture has not been reported, but the radula (tooth structure) of the chitons is known to contain calcium phosphate

Current-induced dynamics in carbon atomic contacts

• Jing-Tao Lü,
• Tue Gunst,
• Per Hedegård and
• Mads Brandbyge

Beilstein J. Nanotechnol. 2011, 2, 814–823, doi:10.3762/bjnano.2.90

• thermodynamic equilibrium, ξ is characterized by a temperature and is related to Πr by the fluctuation-dissipation theorem. Note that in general x, F, and ξ are vectors and Πr is a matrix. This method was used by Wang and co-workers [28][29] to describe thermal transport in the quantum limit, with phonons in

• linearly coupled harmonic phonon bath is similar, and was given in [28]. Alternatively, the dynamics of some external phonons, not coupling to the electrons directly, may be treated explicitly in actual MD calculations, as we illustrate below (regions DL, DR in Figure 6a). The electron–phonon coupling

• + 1) is the Fermi-Dirac distribution function. We thus treat the nonequilibrium electron system as a reservoir unperturbed by the phonons. Using the nonequilibrium Greens function (NEGF) technique [36], we may write the 2nd lowest orders in M of as, The first term yields a constant force due to the

Nonconservative current-induced forces: A physical interpretation

• Tchavdar N. Todorov,
• Daniel Dundas,
• Anthony T. Paxton and
• Andrew P. Horsfield

Beilstein J. Nanotechnol. 2011, 2, 727–733, doi:10.3762/bjnano.2.79

• emission of directional phonons. This connection with electron–phonon interactions quantifies explicitly the intuitive notion that nonconservative forces work by angular momentum transfer. Keywords: atomic-scale conductors; current-induced forces; failure mechanisms; nanomotors; Introduction Electron

• phonons, characterised by the sign of their angular momentum. This second result will close the gap between the nonconservative effect and the more familiar fundamental physics of electron–phonon interactions. Results and Discussion The gas-flow picture Under steady-state conditions, in the absence of

• phonons, the electronic properties of a nanoscale conductor are parametric functions of the classical nuclear positions. So too are the current-induced forces on the nuclei. The nonconservative component of these forces is characterised by the generalised curl expression [12][18] Here, and throughout the

Towards a scalable and accurate quantum approach for describing vibrations of molecule–metal interfaces

• David M. Benoit,
• Bruno Madebene,
• Inga Ulusoy,
• Luis Mancera,
• Yohann Scribano and
• Sergey Chulkov

Beilstein J. Nanotechnol. 2011, 2, 427–447, doi:10.3762/bjnano.2.48

Charge transfer through single molecule contacts: How reliable are rate descriptions?

• Denis Kast,
• L. Kecke and
• J. Ankerhold

Beilstein J. Nanotechnol. 2011, 2, 416–426, doi:10.3762/bjnano.2.47

• , intramolecular phonons are distributed according to a voltage driven steady state that can only roughly be captured by a thermal distribution with an effective elevated temperature (heating). An extension of a master equation for the charge–phonon complex, to effectively include the impact of off-diagonal

• ) is the Fermi distribution. Inelastic tunneling associated with energy emission/absorption of phonons is captured by the Fourier transform of the phonon–phonon correlation exp[J(t)] leading to with denoting the mean values for single phonon absorption (a) and emission (e). The exponentials in the

• one can exploit the fact that for vanishing charge–phonon coupling the model can be solved exactly. 3 Master equation for nonequilibrated phonons To derive an equation of motion for the combined dynamics of charge and phonon degrees of freedom, one starts from a Liouville–von Neumann equation for the

The description of friction of silicon MEMS with surface roughness: virtues and limitations of a stochastic Prandtl–Tomlinson model and the simulation of vibration-induced friction reduction

• W. Merlijn van Spengen,
• Viviane Turq and
• Joost W. M. Frenken

Beilstein J. Nanotechnol. 2010, 1, 163–171, doi:10.3762/bjnano.1.20

• energy to really dissipate. In every slip, the stored elastic energy is suddenly released and contributes to a rise of the temperature of the sliding interface and eventually the whole MEMS device due to the thermalization of the phonons launched into the structure upon the impact of the contacting